The best time to visit Kollam is during the cooler, drier months, specifically from October to March.During this period, the weather is pleasantly warm with lower humidity, making it ideal for exploring the backwaters, beaches, and local attractions. You'll find it comfortable for outdoor activities like houseboat cruises on Ashtamudi Lake or visiting the Thangassery Lighthouse.April and May are the hottest months, with high temperatures and increasing humidity, which can make sightseeing less comfortable. The monsoon season, from June to September, brings heavy rainfall.